April is a bad month if your name is Frosty the Snowman. The month of April has on average 10 million km2 less snow coverage than March does. That means there are vast quantities of snow melting around the entire Northern Hemisphere. March of 2011 had the highest snow extent since 1985, but April decided to take a different approach. April was the first month of 2011 to have a negative snow anomaly. As a result there was a very large drop in snow coverage from March to April.